-Add physical block compression to HAMMER2. In HAMMER2 the a block reference describes a logical block and points to a physical block. The physical block can be a different size than the logical block, thus it is possible to implement a compression algorithm to reduce physical space use on a block-by-block basis.

+##### Kernel - Add support for more CPUs

-* Add a hammer2 utility command and associated ioctl to set the compression mode on a directory, to be inherited by any new files or subdirectories created therein.

+DragonFly is currently limited to 63 CPU cores. Servers with more core than that are becoming sort of available or even potentially affordable. Supporting a number of cores greater than 63 is the first step in really testing SMP.

-* Implement one compression algorithm capable of doing block compression on a 64KB block of data. The compression succeeds if it is able to compress at least 50% (down to 32KB), in powers of 2 (16KB, 8KB, etc), and the block is written uncompressed otherwise.